Spermathecae from eight mature female Larch Mountain salamanders (Plethodon larselli) were used to study cellular changes accompanying the administration of ovulation-inducing pregnant mare serum gonadotropin (PMSG). Animals injected daily with 25 IU of PMSG were sacrificed on day 2 or day 4. Ultrastructural alterations of the spermathecal tubules include an increase in the synthesis and release of product into the lumen and hypertrophy of two epithelial cell types by day 4. One cell type exhibits apocrine blebs and is covered with microvilli; the other contains large spherical vesicles and has only a few, short microvilli on its surface. These changes apparently reflect the spermatheca's response to impending ovulation and its involvement in reactivating the stored sperm.
Davitt, Christine M. and Larsen, John H. Jr.
"Scanning Electron Microscopy of the Spermatheca of Plethodon Larselli (Amphibia: Plethodontidae): Changes in the Surface Morphology of the Spermathecal Tubule Prior to Ovulation,"
Scanning Microscopy: Vol. 2
, Article 49.
Available at: https://digitalcommons.usu.edu/microscopy/vol2/iss3/49